9/11 15 years later: 'The grief never goes away'
{{#rendered}} {{/rendered}}FILE- In this Sept. 11, 2015 file photo, a woman holds up a photograph during the ceremony commemorating the Sept. 11, 2001 terrorist attacks at the World Trade Center site in New York. Victims' relatives and dignitaries will once again convene Sunday, Sept. 11, 2016, on the memorial plaza at the World Trade Center for one of the constants in how America remembers 9/11 after 15 years, the anniversary ceremony itself. (AP Photo/Bryan R. Smith, File)
Mourners hold a photo of their loved one during the 15th anniversary of the attacks of the World Trade Center at the National September 11 Memorial, Sunday, Sept. 11, 2016, in New York. (AP Photo/Mary Altaffer) (Copyright 2016 The Associated Press. All rights reserved.)
Mourners hold photos of their loved ones during the 15th anniversary of the attacks of the World Trade Center at the National September 11 Memorial, Sunday, Sept. 11, 2016, in New York. (AP Photo/Mary Altaffer) (Copyright 2016 The Associated Press. All rights reserved.)
A mourner holds a photo of their loved one during the 15th anniversary of the attacks of the World Trade Center at the National September 11 Memorial, Sunday, Sept. 11, 2016, in New York. (AP Photo/Mary Altaffer) (Copyright 2016 The Associated Press. All rights reserved.)
A tour guide, right foreground holding yellow flower, talks to visitors in front of Ladder Co. 10 Engine Co. 10 during a tour of the National September 11 Memorial, Saturday, Sept. 10, 2016, in New York. Sunday marks the 15th anniversary of the attacks on the World Trade Center. (AP Photo/Mary Altaffer) (Copyright 2016 The Associated Press. All rights reserved.)
Mourners arrive for the 15th anniversary ceremony of the attacks of the World Trade Center at the National September 11 Memorial, Sunday, Sept. 11, 2016, in New York. (AP Photo/Mary Altaffer) (Copyright 2016 The Associated Press. All rights reserved.)